There are several obstacles to minimize damages caused by vehicle theft, and among them is the quick recovery. The recovery of a stolen vehicle hinges on early notification about the theft and quick localization of the vehicle. Currently, many theft prevention and recovery systems are available for consumers, but most of them either do not address the problems above simultaneously or are expensive for most car owners.
A typical automobile theft prevention device includes sensors disposed around a vehicle that detect designated events. These designated events typically include unauthorized entry, excessive movement of the vehicle, unauthorized attempts to start the vehicle, and unauthorized attempts to remove one or more components located within the vehicle. Unauthorized entry events typically include the opening of the hood, the opening of the trunk, and the opening of the vehicle's doors. One or more motion sensor is typically used to determine whether there is sufficient movement of the vehicle so as to indicate a possible theft. This provides a triggering of the alarm when there is an attempt to tow the vehicle or place the vehicle on a car carrier. Unauthorized attempts to start the car also indicate possible vehicle theft. In addition, attempts to remove a component such as a stereo or a CD player also may indicate a possible theft.
Upon occurrence of an unauthorized event, the alarm triggers as an attempt to scare the thief off. However, the owner is not notified, unless the owner is nearby and able to hear the alarm. When the owner realizes the vehicle is stolen, often the vehicle is miles away and the owner is powerless to do anything.
Some inventions have been made to allow vehicle owners to remotely shut down vehicles after they have been stolen. A system that provides this capability through wireless transmission technology is described in U.S. Pat. No. 5,276,728, Remotely Activated Automobile Disabling System, to Pagiliaroli (Jan. 4, 1994), which is hereto incorporated by reference. However, Pagiliaroli's system does not provide any indication about the location of a stolen vehicle after it has been disabled.
Once the vehicle is stolen, the recovery is not easy, unless it can be located rapidly. There are few devices that aid vehicle recovery, and a well known one is LOJACK™. LOJACK™ is a relative expensive system that provides after-the-fact retrieval system. The system requires local law enforcement agencies to be equipped with a special tracking system besides an individual device to be installed on vehicles. The device is always in a receiving mode and it is triggered by a radio signal. After the system is triggered, it emits a radio signal, which has a ground range of only a few miles, that allows law enforcement personnel to track its location and ultimately to locate the vehicle.
Another well-known system is OnStar™, which uses Global Positioning System for locating a vehicle and wireless telephone network for communicating with its occupants. Global Positioning System (GPS) satellite technology works by measuring how long it takes a radio signal from a satellite to reach a vehicle, and then calculating distance using that time. Radio waves travel at the speed of light, which is 186,000 miles per second. GPS satellites are launched into very precise orbits and are constantly monitored by the Department of Defense to measure their altitude, position, and speed. Both the satellite and the GPS receiver in the vehicle are generating the same signal, called a pseudo-random code. OnStar™ can calculate the time by comparing how late the satellite's pseudo-random code is compared to the receiver's. That time difference is then multiplied by 186,000 miles per second, giving a vehicle's distance from one satellite. To get the most accurate vehicle location, OnStar™ uses the measurement from four satellites.
The aforementioned systems either require special support from local law enforcement authorities to locate the stolen vehicles or require the vehicles to be equipped with expensive GPS tracking equipment for determining their locations.